Mannitol-Egg Yolk-Polymyxin (MYP) Agar

Principle
MYP Agar Base is also referred to as Mannitol-Egg Yolk-Polymyxin Agar. Mossel et al. (1998) developed
MYP Agar for the isolation of Bacillus cereus in foods. MYP Agar Base is recommended by FDA BAM
M95 to isolate and enumerate B. cereus from foods. This medium differentiates B. cereus from other
bacteria on the basis of lecithinase activity, mannitol fermentation and resistance to polymyxin. Peptone and
meat extract provide nitrogen and carbon source, long chain amino acids, vitamins and other essential
nutrients. Mannitol acts as the carbon source that upon fermentation changes color of medium from red to
yellow. Phenol red is pH indicator dye use to check Mannitol fermentation. Egg yolk emulsion aids in the
differentiation of lecithinase producing colonies, which are surrounded by a zone of white precipitate.
Polymixin B Sulphate acts as the inhibitor to restrict the growth of gram negative bacteria. These properties
also help in the differentiation of B. cereus from other bacillus species.
Use: Recommended for the isolation and identification of Bacillus cereus in accordance with FDA BAM.
Contents*

* Formula adjusted for optimum performance and parameters